using System;
using System.Drawing;
using System.Windows.Forms;

namespace Example2_3_2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            SetStyle(ControlStyles.ResizeRedraw, true);
            this.BackColor = Color.White;
            this.Width = 340;
            this.Height = 340;
        }

        protected override void OnPaint(PaintEventArgs e)
        {
            Graphics g = e.Graphics;

            int width = 30;
            int height = 128;
            int y = 10;
            // Create opaque color maps with alpha = 255:
            ColorMap cm = new ColorMap();
            Font aFont = new Font("Arial", 20, FontStyle.Bold);
            g.DrawString("OPAQUE COLOR", aFont, Brushes.Black, 10, 60);
            DrawColorBar(g, 10, y, width, height, cm, "Spring");
            DrawColorBar(g, 10 + 40, y, width, height, cm, "Summer");
            DrawColorBar(g, 10 + 2 * 40, y, width, height, cm, "Autumn");
            DrawColorBar(g, 10 + 3 * 40, y, width, height, cm, "Winter");
            DrawColorBar(g, 10 + 4 * 40, y, width, height, cm, "Jet");
            DrawColorBar(g, 10 + 5 * 40, y, width, height, cm, "Gray");
            DrawColorBar(g, 10 + 6 * 40, y, width, height, cm, "Hot");
            DrawColorBar(g, 10 + 7 * 40, y, width, height, cm, "Cool");

            y = y + 150;
            // Create transparent color maps with alpha = 150:
            ColorMap cm1 = new ColorMap(64, 150);
            g.DrawString("TRANSPARENT COLOR", aFont, Brushes.Black, 10, 210);
            DrawColorBar(g, 10, y, width, height, cm1, "Spring");
            DrawColorBar(g, 10 + 40, y, width, height, cm1, "Summer");
            DrawColorBar(g, 10 + 2 * 40, y, width, height, cm1, "Autumn");
            DrawColorBar(g, 10 + 3 * 40, y, width, height, cm1, "Winter");
            DrawColorBar(g, 10 + 4 * 40, y, width, height, cm1, "Jet");
            DrawColorBar(g, 10 + 5 * 40, y, width, height, cm1, "Gray");
            DrawColorBar(g, 10 + 6 * 40, y, width, height, cm1, "Hot");
            DrawColorBar(g, 10 + 7 * 40, y, width, height, cm1, "Cool");
        }

        private void DrawColorBar(Graphics g, int x, int y, int width, int height, 
            ColorMap map, string str)
        {
            int[,] cmap = new int[64, 4];
            switch(str)
            {
                case "Jet":
                    cmap = map.Jet();
                    break;
                case "Hot":
                    cmap = map.Hot();
                    break;
                case "Gray":
                    cmap = map.Gray();
                    break;
                case "Cool":
                    cmap = map.Cool();
                    break;
                case "Summer":
                    cmap = map.Summer();
                    break;
                case "Autumn":
                    cmap = map.Autumn();
                    break;
                case "Spring":
                    cmap = map.Spring();
                    break;
                case "Winter":
                    cmap = map.Winter();
                    break;
            }

            int ymin = 0;
            int ymax = 32;
            int dy = height / (ymax - ymin);
            int m = 64;
            for (int i = 0; i < 32; i++)
            {
                int colorIndex = (int)((i - ymin) * m / (ymax - ymin));
                SolidBrush aBrush = new SolidBrush(Color.FromArgb(
                    cmap[colorIndex, 0], cmap[colorIndex, 1],
                    cmap[colorIndex, 2], cmap[colorIndex, 3]));
                g.FillRectangle(aBrush, x, y + i * dy, width, dy);
            }
        }
    }
}